Hearing loss is the most frequent sensory defect in humans. Congenital, perinatal or eariy onset hearing loss occurs in approximately 7 out of 1000 neonates in the United States. In approximately half of the children born with severe hearing impairment, a genetic contribution is suspected. The powerful molecular and genetic techniques available in zebrafish and mouse combined with the functional similarities between mouse and human audition make these organism useful model systems for studying deafness. Core D supports users of genetic models to study genes affecting auditory, vestibular and olfactory system function. We provide technical support in the form of expert mouse husbandry (receiving, setting up crosses, weaning, fostering, background transfers, etc), genotyping, and notification/delivery of requested mice to the users. Core D also supports several facilities for behavioral and physiological analyses of mutants including auditory brainstem responses (ABR), simple motor tests, rotarod testing, and vestibulo-ocular reflex (VOR) analysis. Other services include access to lentiviral transfection technologies and resources for genomic and proteomic data analysis. Advice and training is available to all users from a knowledgeable and helpful Core staff. The Genetics Core will provide greater efficiency for researchers and promote new collaborations between investigators. Quarteriy user meetings provide information on Core resources, discussion of protocols, and talks by Core users on their own research projects currently being pursued. Our goal is to facilitate the use of genetic models to broaden our knowledge of communicafive disorders toward improving human health.